Iran deal: State Department nuclear expert quits after Trump withdraws US from agreement

A top nuclear expert has resigned from the US State Department after Donald Trump announced the US would pull out from the Iran nuclear deal. Richard Johnson, the assistant coordinator for Iran nuclear issues at the Office of Nuclear Implementation, reportedly handed in his resignation this week. A civil servant, Mr Johnson had been involved in failed negotiations including the UK, France and Germany to save the deals after Mr Trump threatened to pull out.